Macrosphelides are macrolide compounds that have a 16-membered ring structure. For example, isolation and structure determination of known macrosphelides A to L, which are expressed by the following formulas, has been achieved using Microsphaeropsis sp. F0-5050 and Periconia byssoides OPUS-N133.
 Macrosphelide A:X = α-OH, β-HMacrosphelide E:X = α-OH, β-HY = α-OH, β-HY = α-OH, β-HMacrosphelide B:X = O, Y =α-OH, β-HMacrosphetide F:X = α-OH, β-HMacrosphelide C:X = α-OH, β-HY = α-H, β-HY = α-OH, β-HMacrosphelide G:X = α-H, β-HY = α-OH, β-H  Macrosphelide I:X = α-OH, β-HMacrosphelide DY = α-OH, β-HMacrosphelide L:X = O, Y = α-OH, β-H  Macrosphelide HMacrosphelide J:R = OCH3Macrosphelide K:R = OC2H5
It has been shown by tests on cell adhesion inhibition that macrosphelides can inhibit adhesion of human leukemia cells and human vascular endothelial cells depending on concentration. Further, tests using monoclonal antibody have suggested that this action centers on a particle called Sialyl Lewis, which is a particle that influences reduction of adhesion of leucocyte cells or cancer cells to vascular endothelial cells. Moreover, it has also become apparent that macrosphelides do not cause any significant growth inhibition or have toxicity for various mammals, and thus there are growing expectations for their use as a lead compound for specific cancer spread inhibiting drugs that can be practically applied.
As the noteworthy biological activity of macrosphelides has become clear as described above, recently, research about total synthesis of macrosphelides has started to be reported. At present, as a result of research by two research groups, asymmetric total synthesis of macrosphelides A, B, C and F has been achieved using the convergent synthesis strategies shown below.

Recently, continuing research on macrosphelides has focused on the correlative relationship of their structure and effects with respect to not only biological adhesion inhibition activity, but also anti-virus activity and immunity suppression action. For this research, synthesis of natural and non-natural macrosphelides including derivatives and stereoisomers is essential. However, the synthesis methods for the above all use asymmetric induction reactions such as asymmetric oxidation or kinetic optical resolution, and the objective of the synthesis is to produce specific macrosphelides. Accordingly, application to other types of macrosphelides synthesis is not possible. Moreover, the above synthesis methods also suffer from the problem of having low yields of around 10%.
The present invention has been conceived of in light of the above described circumstances, and it is an object thereof to provide a new synthesis method that allows high yield synthesis of a macrosphelide core that provides a core for obtaining multiple different types of macrosphelide deviates.